AT137768B - Optical light meter, in particular for photography. - Google Patents
Optical light meter, in particular for photography.Info
- Publication number
- AT137768B AT137768B AT137768DA AT137768B AT 137768 B AT137768 B AT 137768B AT 137768D A AT137768D A AT 137768DA AT 137768 B AT137768 B AT 137768B
- Authority
- AT
- Austria
- Prior art keywords
- photography
- optical light
- light meter
- desc
- light
- Prior art date
Links
Landscapes
- Eye Examination Apparatus (AREA)
- Photometry And Measurement Of Optical Pulse Characteristics (AREA)
Description
<Desc/Clms Page number 1>
Optischer Lichtmesser, insbesondere für Photographie.
Ein Photometer nach dem Stammpatent, bei dem die Empfindlichkeit des Auges durch Verdunklung einer elektrischen Glühlampe gemessen wird, kann auch derart ausgeführt werden, dass der Apparat bei der Lichtmessung in normaler Sehweite gehalten wird. Die Glühlampe 6 (Fig. 1) befindet sich dann in einer Dunkelkammer 1, durch deren Loch 2 der Glühfaden sichtbar ist, während durch Loch 3 und 4 das zu messende Licht in das Auge fällt. Die glänzenden Oberflächen der Graukeile 5 und 7 stehen dann erfindungsgemäss zu den Sehachsen 8 und 9 in einem Winkel, der grösser oder kleiner ist als 90 , so dass von ihnen reflektiertes Licht in das Innere der geschwärzten Kammer 1 geworfen wird.
Dadurch wird vermieden, dass durch die Löcher 2 und 4 kommendes, die Messung verfälschendes Licht zurück in das messende Auge reflektiert wird. Bei zylindrischer Ausführung des Instruments müssen die Graukeile konisch gestaltet sein.
**WARNUNG** Ende DESC Feld kannt Anfang CLMS uberlappen**.
<Desc / Clms Page number 1>
Optical light meter, in particular for photography.
A photometer according to the parent patent, in which the sensitivity of the eye is measured by darkening an electric incandescent lamp, can also be designed in such a way that the apparatus is kept within normal visual range when measuring light. The incandescent lamp 6 (FIG. 1) is then located in a darkroom 1, through the hole 2 of which the filament is visible, while the light to be measured falls into the eye through holes 3 and 4. According to the invention, the shiny surfaces of the gray wedges 5 and 7 are at an angle to the visual axes 8 and 9 which is greater or less than 90, so that light reflected from them is thrown into the interior of the blackened chamber 1.
This prevents light coming through the holes 2 and 4 and falsifying the measurement from being reflected back into the measuring eye. If the instrument is cylindrical, the gray wedges must be conical.
** WARNING ** End of DESC field may overlap beginning of CLMS **.
Claims (1)
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AT132246T | 1932-01-07 | ||
| AT137768T | 1933-02-18 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| AT137768B true AT137768B (en) | 1934-05-25 |
Family
ID=34218415
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| AT137768D AT137768B (en) | 1932-01-07 | 1933-02-18 | Optical light meter, in particular for photography. |
Country Status (1)
| Country | Link |
|---|---|
| AT (1) | AT137768B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2491654A (en) * | 1946-09-06 | 1949-12-20 | John L Foust | Exposure meter having object and comparison gray scale means |
-
1933
- 1933-02-18 AT AT137768D patent/AT137768B/en active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2491654A (en) * | 1946-09-06 | 1949-12-20 | John L Foust | Exposure meter having object and comparison gray scale means |
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